"We were quite surprised that Casey was available for a trade and we pounced on it," United general manager Dave Kasper said in a written statement. "He is an exciting striker who brings a ton of energy to the attack, and we think he will be a great fit with our side."

Kasper shouldn't have been too surprised. Chivas USA, owned by Chivas Guadalajara and guided by first-year coach Jose Luis Sanchez Sola of Mexico, is emphasizing a Mexican and Mexican-American roster to find a foothold in the Southern California market.

Said one observer close to the situation: United "got a steal."

Townsend, 23, bolsters a front line that added Rafael, 20, on loan from Brazil's Bahia this month. United's other options are Canadian veteran Dwayne De Rosario, who also plays in midfield, and Colombian Lionard Pajoy.

Later on Friday, United released another forward, Chinese reserve Long Tan.